3.0 TDI - Oil Leak

[Pyrotechnic]

Hello All,

I have a 2009 (B8) A4 saloon with the 3.0TDI engine.

Around March time it developed an oil leak. After ignoring it for a couple of months and just topping it up every so often, I finally took it to a specialist. They diagnosed that it was coming from the exhaust manifolds (both sides) and without removing the engine and then manifolds, that's as far as they could go.

I got the car back and took it to a local garage instead for them to work on it (half the hourly wage...)
He (and everyone else I've mentioned it to) didn't believe it could leak from there and said he'd have a look before going ahead with removing the engine and said he suspected the valve covers.

Spoken to him today, and he's confirmed it is indeed leaking from both exhaust manifolds... (above is dry)

Some facts:

1) It started leaking just after a service and Terraclean.
2) It drives absolutely fine, no loss of power or economy (getting 40+ mpg, even got 46 the other day).
3) It doesn't smoke, at all (which no-one can understand either. Surely if there's oil in the exhaust, there should be large, black clouds coming out the back...).
4) DPF is dry.
5) Turbo intake has a slight misting (he seemed to imply this was normal I think?)
6) Mentioned EGR pipes were also wet.

He's suggested either turbo or even an internal crack in the engine. He's still got the car is going to speak to a friend who is a MT at Audi to see if he's got any ideas.

Everyone I speak to says these engines are bullet-proof. Trust me to get the duff one.

Any idea?

 

[Emmo]

I've seen a similar thing when I had my b7 3.0 tdi.
There was an oil leak, which had the mechanics baffled, initially thought to be rocker cover gaskets, both sides replaced but still finding oil on the drive.

Eventually got traced to coming from the exhaust manifolds on both sides.
After stripping down, it was found there were some holes on both sides with possibly some blanking plugs missing.

Mechanic used some really small bolts and fitted them in with some sealant and cut the heads off flush.
Refitted manifolds and no more oil leaks.

It had them baffled for a long time, only got found with the car on the ramp.
Subframe off and cleaning all the oil off as it was everywhere on the underside, the engine was run and a tiny tiny drip could be seen emerging from the studs on the manifold.

Before this was found, rocker gaskets were done aswell as oil seal on the front. Due to the oil coating everything it was difficult to trace.

Not sure if the b8 3.0 tdi is similar but it could be something to look at.

 

[desertstorm]

After a bit of googling as I have an interest in this engine.Found this thread.
http://www.pistonheads.com/gassing/topic.asp?t=1371928
I suspect that the terraclean has removed carbon deposits on the injector seals that were stopping them leaking. They are now leaking and I suspect this is what you are seeing.

Looks like the fix to me is removal of injectors and replacement of seals and don't Terraclean it again.
Not sure if it's the internal seals on the injectors that are leaking as these are the ones that would have been exposed to the Terraclean.
If an injector was to leak and there was no where for the leaking diesel to go it would end up rising into the the top of the injector and finding it's way into the engine oil where it would eventually fill the sump. So a good idea to allow an escape path for leaking diesel.
You should be able to identify which injectors are leaking by the location of the leaks on the manifold.

 

[Pyrotechnic]

Many thanks guys! Have suggested this to my mechanic and he's going to remove a few injectors and see what that reveals.

Emmo, hopefully going by 'when I had' means you no longer have that car, as it sounds like those hole shouldn't be blocked up...

Karl, you're obviously better at the internet than me, I couldn't find anything! Been following your thread on and off for a while, very impressive. I try not to follow too closely as I feel it could get quite expensive for myself ;]

 

[Emmo]

Yes I no longer own that and have a b8 3.0 tdi.
I did run the car for over a year after the repair with no leaks, I think there was supposed to be some sort of blank plug in the holes.

 

[jdp1962]

I suspect that the terraclean has removed carbon deposits on the injector seals that were stopping them leaking. They are now leaking and I suspect this is what you are seeing. Looks like the fix to me is removal of injectors and replacement of seals and don't Terraclean it again.
.

This reminds me of when Mobil 1 was first launched in the mid 1980s. Loads of people used it in their old high-mileage cars thinking it would give the engine a new lease of life. In fact, all it did was flush out all of the gunk and carbon deposits that had been the only thing holding the engine together. A week later, and most of the shiny smooth new Mobil 1 oil was lying on the ground.

 

[Pyrotechnic]

Mechanic is replacing the seals, should get it back tonight hopefully, then fingers crossed.

Also, found this gem in an old invoice I got with the car...

 

[scotty76]

Mechanic is replacing the seals, should get it back tonight hopefully, then fingers crossed.

Also, found this gem in an old invoice I got with the car...

Ouch bet that wasn't cheap.

 

[Pyrotechnic]

Ouch bet that wasn't cheap.

Even at ~£750 it was still one of the cheaper invoices I found in the history, which makes it even more mind-boggling that they didn't replace the seals, especially since the injectors were obviously already removed!

 

[desertstorm]

Well that looks promising to be the cause of your issue. I cannot believe the seals weren't replaced if they were missing.